The probiotic bacteria, among which the most common are the lactose fermenting Lactobacilli, inhibit the growth of pathogenic bacteria by acidifying the gut lumen, competing for nutrients, and by producing antimicrobial substances. They adhere to the gut mucosa and by that are thought to prevent bacterial translocation from the gut. These effects of probiotics raised the idea that they may have a role in the treatment and prevention of cirrhosis complications. A recent study examined the effect of probiotics on patients with minimal chronic hepatic encephalopathy. Hepatic encephalopathy was reversed in 50% of the patients receiving probiotics. These patients also demonstrated a significant reduction of blood levels of ammonia, bilirubin and ALT, and of pathologic bacteria in stool cultures. This study showed promising results but was carried out on a relatively small population. Furthermore, the effect of probiotics on the prevention of hepatic encephalopathy and other major complications of cirrhosis has not been studied yet. Therefore, more studies are needed to establish the role of probiotics in patients with cirrhosis.